1,137 research outputs found

    The inferior caval vein draining into the left atrial cavity : a rare case

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    The inferior vena cava (IVC) draining into the left atrium (LA) is exceedingly rare in the setting of the usual atrial arrangement (situs solitus). This article describes a patient with this unique anomaly, and its repair.peer-reviewe

    Hedgehog signal transduction proteins: contacts of the Fused kinase and Ci transcription factor with the Kinesin-related protein Costal2

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    BACKGROUND: Hedgehog signaling proteins play important roles in development by controlling growth and patterning in various animals including Drosophila and mammals. Hedgehog signaling triggers changes in responsive cells through a novel transduction mechanism that ultimately controls the transcription of specific target genes via the activity of zinc finger transcription factors of the Cubitus interruptus /GLI family. In flies, key Hedgehog signal transduction components have been identified including the kinesin-related protein Costal2, the serinethreonine kinase Fused, and the PEST-containing protein Suppressor of Fused. These proteins control Cubitus interruptus cleavage, nucleo-cytoplasmic localization and activation. In fly embryos, Costal2, Fused, Suppressor of Fused and Cubitus interruptus are associated in at least one cytoplasmic complex, which interacts with the microtubules in a Hedgehog-dependent manner. RESULTS: Here we identified and mapped direct interactions between Cos2, Fu, and Ci using an in vitro affinity assay and the yeast two-hybrid system. CONCLUSIONS: Our results provide new insights into the possible mechanism of the cytosolic steps of Hedgehog transduction

    Identification of transcription-factor genes expressed in the Arabidopsis female gametophyte

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    Dongfang Wang, Changqing Zhang, David J. Hearn, Il-HO Kang, megan I. Skaggs, Karen S. Schumaker, and Ramin Yadegari are with the School of Plant Sciences, University of Arizona, Tucson, Arizona 85721-0036, USA -- Il-Ho Kang, Jayson A. Punwani, and Gary N. Drews are with the Department of Biology, University of Utah, Salt Lake City, Utah 84112-0840, USA -- Changqing Zhang is with The Section of Molecular, Cell and Developmental Biology, University of Texas at Austin, Austin, Texas 78712-0159, USA -- David J. Hearn is with the Department of Biological Sciences, Towson University, Towson, Maryland 21252-0001, USA -- Il-Ho Kang is with the Department of Horticulture, Iowa State University, Ames, Iowa 50011-1100, USA --Jayson A. Punwani is with the Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3280, USABackground In flowering plants, the female gametophyte is typically a seven-celled structure with four cell types: the egg cell, the central cell, the synergid cells, and the antipodal cells. These cells perform essential functions required for double fertilization and early seed development. Differentiation of these distinct cell types likely involves coordinated changes in gene expression regulated by transcription factors. Therefore, understanding female gametophyte cell differentiation and function will require dissection of the gene regulatory networks operating in each of the cell types. These efforts have been hampered because few transcription factor genes expressed in the female gametophyte have been identified. To identify such genes, we undertook a large-scale differential expression screen followed by promoter-fusion analysis to detect transcription-factor genes transcribed in the Arabidopsis female gametophyte. Results Using quantitative reverse-transcriptase PCR, we analyzed 1,482 Arabidopsis transcription-factor genes and identified 26 genes exhibiting reduced mRNA levels in determinate infertile 1 mutant ovaries, which lack female gametophytes, relative to ovaries containing female gametophytes. Spatial patterns of gene transcription within the mature female gametophyte were identified for 17 transcription-factor genes using promoter-fusion analysis. Of these, ten genes were predominantly expressed in a single cell type of the female gametophyte including the egg cell, central cell and the antipodal cells whereas the remaining seven genes were expressed in two or more cell types. After fertilization, 12 genes were transcriptionally active in the developing embryo and/or endosperm. Conclusions We have shown that our quantitative reverse-transcriptase PCR differential-expression screen is sufficiently sensitive to detect transcription-factor genes transcribed in the female gametophyte. Most of the genes identified in this study have not been reported previously as being expressed in the female gametophyte. Therefore, they might represent novel regulators and provide entry points for reverse genetic and molecular approaches to uncover the gene regulatory networks underlying female gametophyte development.Cellular and Molecular [email protected]

    Cyclin D1 repressor domain mediates proliferation and survival in prostate cancer.

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    Regulation of the androgen receptor (AR) is critical to prostate cancer (PCa) development; therefore, AR is the first line therapeutic target for disseminated tumors. Cell cycle-dependent accumulation of cyclin D1 negatively modulates the transcriptional regulation of AR through discrete, CDK4-independent mechanisms. The transcriptional corepressor function of cyclin D1 resides within a defined motif termed repressor domain (RD), and it was hypothesized that this motif could be utilized as a platform to develop new strategies for blocking AR function. Here, we demonstrate that expression of the RD peptide is sufficient to disrupt AR transcriptional activation of multiple, prostate-specific AR target genes. Importantly, these actions are sufficient to specifically inhibit S-phase progression in AR-positive PCa cells, but not in AR-negative cells or tested AR-positive cells of other lineages. As expected, impaired cell cycle progression resulted in a suppression of cell doubling. Additionally, cell death was observed in AR-positive cells that maintain androgen dependence and in a subset of castrate-resistant PCa cells, dependent on Akt activation status. Lastly, the ability of RD to cooperate with existing hormone therapies was examined, which revealed that RD enhanced the cellular response to an AR antagonist. Together, these data demonstrate that RD is sufficient to disrupt AR-dependent transcriptional and proliferative responses in PCa, and can enhance efficacy of AR antagonists, thus establishing the impetus for development of RD-based mimetics

    NiO/nanoporous carbon heterogeneous Fenton catalyst for aqueous microcystine-LR decomposition

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    The efficacy of NiO nanoparticles dispersed on a nanoporous carbon matrix (NiO/NPC) for microcystine-LR degradation in aqueous media is reported. The NiO/NPC catalyst was characterized by porosimetry, scanning electron microscopy, elemental analysis, powder X-ray diffraction, and X-ray photoelectron spectroscopy, and applied to the oxidative degradation of microcystine-LR contaminated water in the presence of hydrogen peroxide as a function of pH under ambient conditions. Optimal MC-LR removal efficiency was 86% at neutral pH catalyzed by this heterogeneous Fenton-like (NiO/NPC with H2O2) process, which has the added benefit of avoiding secondary metal pollution during microcystine-LR degradation. NiO/NPC represents an earth abundant catalyst for generating hydroxyl radicals to facilitate environmental depollution of organic pollutants from wastewater

    Systematic quantitative characterization of cellular responses induced by multiple signals

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    <p>Abstract</p> <p>Background</p> <p>Cells constantly sense many internal and environmental signals and respond through their complex signaling network, leading to particular biological outcomes. However, a systematic characterization and optimization of multi-signal responses remains a pressing challenge to traditional experimental approaches due to the arising complexity associated with the increasing number of signals and their intensities.</p> <p>Results</p> <p>We established and validated a data-driven mathematical approach to systematically characterize signal-response relationships. Our results demonstrate how mathematical learning algorithms can enable systematic characterization of multi-signal induced biological activities. The proposed approach enables identification of input combinations that can result in desired biological responses. In retrospect, the results show that, unlike a single drug, a properly chosen combination of drugs can lead to a significant difference in the responses of different cell types, increasing the differential targeting of certain combinations. The successful validation of identified combinations demonstrates the power of this approach. Moreover, the approach enables examining the efficacy of all lower order mixtures of the tested signals. The approach also enables identification of system-level signaling interactions between the applied signals. Many of the signaling interactions identified were consistent with the literature, and other unknown interactions emerged.</p> <p>Conclusions</p> <p>This approach can facilitate development of systems biology and optimal drug combination therapies for cancer and other diseases and for understanding key interactions within the cellular network upon treatment with multiple signals.</p

    Transcriptional ontogeny of the developing liver

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    <p>Abstract</p> <p>Background</p> <p>During embryogenesis the liver is derived from endodermal cells lining the digestive tract. These endodermal progenitor cells contribute to forming the parenchyma of a number of organs including the liver and pancreas. Early in organogenesis the fetal liver is populated by hematopoietic stem cells, the source for a number of blood cells including nucleated erythrocytes. A comprehensive analysis of the transcriptional changes that occur during the early stages of development to adulthood in the liver was carried out.</p> <p>Results</p> <p>We characterized gene expression changes in the developing mouse liver at gestational days (GD) 11.5, 12.5, 13.5, 14.5, 16.5, and 19 and in the neonate (postnatal day (PND) 7 and 32) compared to that in the adult liver (PND67) using full-genome microarrays. The fetal liver, and to a lesser extent the neonatal liver, exhibited dramatic differences in gene expression compared to adults. Canonical pathway analysis of the fetal liver signature demonstrated increases in functions important in cell replication and DNA fidelity whereas most metabolic pathways of intermediary metabolism were under expressed. Comparison of the dataset to a number of previously published microarray datasets revealed 1) a striking similarity between the fetal liver and that of the pancreas in both mice and humans, 2) a nucleated erythrocyte signature in the fetus and 3) under expression of most xenobiotic metabolism genes throughout development, with the exception of a number of transporters associated with either hematopoietic cells or cell proliferation in hepatocytes.</p> <p>Conclusions</p> <p>Overall, these findings reveal the complexity of gene expression changes during liver development and maturation, and provide a foundation to predict responses to chemical and drug exposure as a function of early life-stages.</p

    Pengaruh Latihan Kegel Terhadap Frekuensi Inkontinensia Urine Pada Lansia Di Unit Rehabilitasi Sosial Margo Mukti Rembang

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    The purpose of this study was to determine the influence of the Kegel exercise on frequency of urinary incontinence in the elderly. This study used a quasi -experimental with one group pre and post test study design, conducted on 27 respondents selected by purposive sampling technique. Respondents were divided into three groups which were the first group with frequency of exercise 2 times, the second group with 3 times and the third group 4 times a day for six weeks. Data on the frequency of urinary incontinence were collected in pre and post intervention Kegel exercise. Data were analyzed using t-test (paired t-test).The results of the study revealed that group I , II &amp; III in sequence value of t-count 21.92, t=11,418 and t=15.307 with P values p=0, 00. Further comparisons between the three groups showed group III showed the mean frequency of urinary incontinence at least. It can be concluded that Kegel exercises affect the decrease in the frequency of urinary incontinence in the elderly, and it is suggested that Kegel exercises should be done regularly

    The SDSS-IV in 2014: a demographic snapshot

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    Many astronomers now participate in large international scientific collaborations, and it is important to examine whether these structures foster a healthy scientific climate that is inclusive and diverse. The Committee on the Participation of Women in the Sloan Digital Sky Survey (CPWS) was formed to evaluate the demographics and gender climate within SDSS-IV, one of the largest and most geographically distributed astronomical collaborations. In April 2014, the CPWS administered a voluntary demographic survey to establish a baseline for the incipient SDSS-IV, which began observations in July 2014. We received responses from 250 participants (46% of the active membership). Half of the survey respondents were located in the United States or Canada and 30% were based in Europe. Approximately 65% were faculty or research scientists and 31% were postdocs or graduate students. Eleven percent of survey respondents considered themselves to be an ethnic minority at their current institution. Twenty-five percent of the SDSS-IV collaboration members are women, a fraction that is consistent with the US astronomical community, but substantially higher than the fraction of women in the International Astronomical Union (16%). Approximately equal fractions of men and women report holding positions of leadership in the collaboration. When binned by academic age and career level, men and women also assume leadership roles at approximately equal rates, in a way that increases steadily for both genders with increasing seniority. In this sense, SDSS-IV has been successful in recruiting leaders that are representative of the collaboration. That said, it is clear that more progress needs to be made towards achieving gender balance and increasing diversity in the field of astronomy, and there is still room for improvement in the membership and leadership of SDSS-IV. For example, at the highest level of SDSS-IV leadership, women disproportionately assume roles related to education and public outreach. The goal of the CPWS is to use these initial data to establish a baseline for tracking demographics over time as we work to assess and improve the climate of SDSS-IV
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